Error when selection enter/view scores on an existing intervention with a new intervention_probe_assignment

ActionView::TemplateError (preview_graph_intervention_probe_assignment_url failed to generate from {:count=>0, :controller=>"interventions/probe_assignments", :intervention_id=>184330823, :action=>"preview_graph", :id=>nil}, expected: {:controller=>"interventions/probe_assignments", :action=>"preview_graph"}, diff: {:count=>0, :intervention_id=>184330823, :id=>nil}) on line #13 of app/views/interventions/probe_assignments/probe_assignment.html.erb:
10: end
11: %>
12:
13: <%= link_to_remote 'Preview Graph', :url => preview_graph_intervention_probe_assignment_path(:intervention_id=>probe_assignment.intervention_id, :id=>probe_assignment.id, :count => probe_assignment_counter), :method => :get, :update => {:success => "graph#{probe_assignment_counter}"}, :with => "new_probe_scores()" %>
14:
15: <% end %>
16: <% else %>

(eval):16:in `preview_graph_intervention_probe_assignment_path'
app/views/interventions/probe_assignments/_probe_assignment.html.erb:13
app/views/interventions/probe_assignments/_probe_assignment.html.erb:4
app/views/interventions/probe_assignments/_index.html.erb:1
app/views/interventions/probe_assignments/index.js.rjs:2:in `__instance_exec0'
app/views/interventions/probe_assignments/index.js.rjs:1:in `_run_rjs_app47views47interventions47probe_assignments47index46js46rjs'
app/controllers/interventions/probe_assignments_controller.rb:10:in `index'

Rendered rescues/trace (106.1ms)
Rendered rescues/request_and_response (2.6ms)
Rendering rescues/layout (internal_server_error)